Summa Theologica Part I (Prima Pars) Part 129

Obj. 2: Further, the intellectual soul is more excellent than corporeal primary matter. But primary matter was created by G.o.d under the forms to which it has potentiality. Therefore much more is the intellectual soul created by G.o.d under intelligible species. And so the soul understands corporeal things through innate species.

Obj. 3: Further, no one can answer the truth except concerning what he knows. But even a person untaught and devoid of acquired knowledge, answers the truth to every question if put to him in orderly fashion, as we find related in the Meno (xv seqq.) of Plato, concerning a certain individual. Therefore we have some knowledge of things even before we acquire knowledge; which would not be the case unless we had innate species. Therefore the soul understands corporeal things through innate species.

_On the contrary,_ The Philosopher, speaking of the intellect, says (De Anima iii, 4) that it is like "a tablet on which nothing is written."

_I answer that,_ Since form is the principle of action, a thing must be related to the form which is the principle of an action, as it is to that action: for instance, if upward motion is from lightness, then that which only potentially moves upwards must needs be only potentially light, but that which actually moves upwards must needs be actually light. Now we observe that man sometimes is only a potential knower, both as to sense and as to intellect. And he is reduced from such potentiality to act--through the action of sensible objects on his senses, to the act of sensation--by instruction or discovery, to the act of understanding. Wherefore we must say that the cognitive soul is in potentiality both to the images which are the principles of sensing, and to those which are the principles of understanding. For this reason Aristotle (De Anima iii, 4) held that the intellect by which the soul understands has no innate species, but is at first in potentiality to all such species.

But since that which has a form actually, is sometimes unable to act according to that form on account of some hindrance, as a light thing may be hindered from moving upwards; for this reason did Plato hold that naturally man's intellect is filled with all intelligible species, but that, by being united to the body, it is hindered from the realization of its act. But this seems to be unreasonable. First, because, if the soul has a natural knowledge of all things, it seems impossible for the soul so far to forget the existence of such knowledge as not to know itself to be possessed thereof: for no man forgets what he knows naturally; that, for instance, the whole is larger than the part, and such like. And especially unreasonable does this seem if we suppose that it is natural to the soul to be united to the body, as we have established above ([Q. 76] , A. 1): for it is unreasonable that the natural operation of a thing be totally hindered by that which belongs to it naturally. Secondly, the falseness of this opinion is clearly proved from the fact that if a sense be wanting, the knowledge of what is apprehended through that sense is wanting also: for instance, a man who is born blind can have no knowledge of colors. This would not be the case if the soul had innate images of all intelligible things. We must therefore conclude that the soul does not know corporeal things through innate species.

Reply Obj. 1: Man indeed has intelligence in common with the angels, but not in the same degree of perfection: just as the lower grades of bodies, which merely exist, according to Gregory (Homily on Ascension, xxix In Ev.), have not the same degree of perfection as the higher bodies. For the matter of the lower bodies is not totally completed by its form, but is in potentiality to forms which it has not: whereas the matter of heavenly bodies is totally completed by its form, so that it is not in potentiality to any other form, as we have said above (Q. 66, A. 2). In the same way the angelic intellect is perfected by intelligible species, in accordance with its nature; whereas the human intellect is in potentiality to such species.

Reply Obj. 2: Primary matter has substantial being through its form, consequently it had need to be created under some form: else it would not be in act. But when once it exists under one form it is in potentiality to others. On the other hand, the intellect does not receive substantial being through the intelligible species; and therefore there is no comparison.

Reply Obj. 3: If questions be put in an orderly fashion they proceed from universal self-evident principles to what is particular. Now by such a process knowledge is produced in the mind of the learner.

Wherefore when he answers the truth to a subsequent question, this is not because he had knowledge previously, but because he thus learns for the first time. For it matters not whether the teacher proceed from universal principles to conclusions by questioning or by a.s.serting; for in either case the mind of the listener is a.s.sured of what follows by that which preceded.

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FOURTH ARTICLE [I, Q. 84, Art. 4]

Whether the Intelligible Species Are Derived by the Soul from Certain Separate Forms?

Objection 1: It would seem that the intelligible species are derived by the soul from some separate forms. For whatever is such by partic.i.p.ation is caused by what is such essentially; for instance, that which is on fire is reduced to fire as the cause thereof. But the intellectual soul forasmuch as it is actually understanding, partic.i.p.ates the thing understood: for, in a way, the intellect in act is the thing understood in act. Therefore what in itself and in its essence is understood in act, is the cause that the intellectual soul actually understands. Now that which in its essence is actually understood is a form existing without matter. Therefore the intelligible species, by which the soul understands, are caused by some separate forms.

Obj. 2: Further, the intelligible is to the intellect, as the sensible is to the sense. But the sensible species which are in the senses, and by which we sense, are caused by the sensible object which exists actually outside the soul. Therefore the intelligible species, by which our intellect understands, are caused by some things actually intelligible, existing outside the soul. But these can be nothing else than forms separate from matter. Therefore the intelligible forms of our intellect are derived from some separate substances.

Obj. 3: Further, whatever is in potentiality is reduced to act by something actual. If, therefore, our intellect, previously in potentiality, afterwards actually understands, this must needs be caused by some intellect which is always in act. But this is a separate intellect. Therefore the intelligible species, by which we actually understand, are caused by some separate substances.

_On the contrary,_ If this were true we should not need the senses in order to understand. And this is proved to be false especially from the fact that if a man be wanting in a sense, he cannot have any knowledge of the sensibles corresponding to that sense.

_I answer that,_ Some have held that the intelligible species of our intellect are derived from certain separate forms or substances. And this in two ways. For Plato, as we have said (A. 1), held that the forms of sensible things subsist by themselves without matter; for instance, the form of a man which he called _per se_ man, and the form or idea of a horse which is called _per se_ horse, and so forth.

He said therefore that these forms are partic.i.p.ated both by our soul and by corporeal matter; by our soul, to the effect of knowledge thereof, and by corporeal matter to the effect of existence: so that, just as corporeal matter by partic.i.p.ating the idea of a stone, becomes an individuating stone, so our intellect, by partic.i.p.ating the idea of a stone, is made to understand a stone. Now partic.i.p.ation of an idea takes place by some image of the idea in the partic.i.p.ator, just as a model is partic.i.p.ated by a copy. So just as he held that the sensible forms, which are in corporeal matter, are derived from the ideas as certain images thereof: so he held that the intelligible species of our intellect are images of the ideas, derived therefrom.

And for this reason, as we have said above (A. 1), he referred sciences and definitions to those ideas.

But since it is contrary to the nature of sensible things that their forms should subsist without matter, as Aristotle proves in many ways (Metaph. vi), Avicenna (De Anima v) setting this opinion aside, held that the intelligible species of all sensible things, instead of subsisting in themselves without matter, pre-exist immaterially in the separate intellects: from the first of which, said he, such species are derived by a second, and so on to the last separate intellect which he called the "active intelligence," from which, according to him, intelligible species flow into our souls, and sensible species into corporeal matter. And so Avicenna agrees with Plato in this, that the intelligible species of our intellect are derived from certain separate forms; but these Plato held to subsist of themselves, while Avicenna placed them in the "active intelligence." They differ, too, in this respect, that Avicenna held that the intelligible species do not remain in our intellect after it has ceased actually to understand, and that it needs to turn (to the active intellect) in order to receive them anew. Consequently he does not hold that the soul has innate knowledge, as Plato, who held that the partic.i.p.ated ideas remain immovably in the soul.

But in this opinion no sufficient reason can be a.s.signed for the soul being united to the body. For it cannot be said that the intellectual soul is united to the body for the sake of the body: for neither is form for the sake of matter, nor is the mover for the sake of the moved, but rather the reverse. Especially does the body seem necessary to the intellectual soul, for the latter's proper operation which is to understand: since as to its being the soul does not depend on the body. But if the soul by its very nature had an inborn apt.i.tude for receiving intelligible species through the influence of only certain separate principles, and were not to receive them from the senses, it would not need the body in order to understand: wherefore to no purpose would it be united to the body.

But if it be said that our soul needs the senses in order to understand, through being in some way awakened by them to the consideration of those things, the intelligible species of which it receives from the separate principles: even this seems an insufficient explanation. For this awakening does not seem necessary to the soul, except in as far as it is overcome by sluggishness, as the Platonists expressed it, and by forgetfulness, through its union with the body: and thus the senses would be of no use to the intellectual soul except for the purpose of removing the obstacle which the soul encounters through its union with the body. Consequently the reason of the union of the soul with the body still remains to be sought.

And if it be said with Avicenna, that the senses are necessary to the soul, because by them it is aroused to turn to the "active intelligence" from which it receives the species: neither is this a sufficient explanation. Because if it is natural for the soul to understand through species derived from the "active intelligence,"

it follows that at times the soul of an individual wanting in one of the senses can turn to the active intelligence, either from the inclination of its very nature, or through being roused by another sense, to the effect of receiving the intelligible species of which the corresponding sensible species are wanting. And thus a man born blind could have knowledge of colors; which is clearly untrue. We must therefore conclude that the intelligible species, by which our soul understands, are not derived from separate forms.

Reply Obj. 1: The intelligible species which are partic.i.p.ated by our intellect are reduced, as to their first cause, to a first principle which is by its essence intelligible--namely, G.o.d. But they proceed from that principle by means of the sensible forms and material things, from which we gather knowledge, as Dionysius says (Div. Nom.

vii).

Reply Obj. 2: Material things, as to the being which they have outside the soul, may be actually sensible, but not actually intelligible. Wherefore there is no comparison between sense and intellect.

Reply Obj. 3: Our pa.s.sive intellect is reduced from potentiality to act by some being in act, that is, by the active intellect, which is a power of the soul, as we have said (Q. 79, A. 4); and not by a separate intelligence, as proximate cause, although perchance as remote cause.

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FIFTH ARTICLE [I, Q. 84, Art. 5]

Whether the Intellectual Soul Knows Material Things in the Eternal Types?

Objection 1: It would seem that the intellectual soul does not know material things in the eternal types. For that in which anything is known must itself be known more and previously. But the intellectual soul of man, in the present state of life, does not know the eternal types: for it does not know G.o.d in Whom the eternal types exist, but is "united to G.o.d as to the unknown," as Dionysius says (Myst.

Theolog. i). Therefore the soul does not know all in the eternal types.

Obj. 2: Further, it is written (Rom. 1:20) that "the invisible things of G.o.d are clearly seen ... by the things that are made." But among the invisible things of G.o.d are the eternal types. Therefore the eternal types are known through creatures and not the converse.

Obj. 3: Further, the eternal types are nothing else but ideas, for Augustine says (QQ. 83, qu. 46) that "ideas are permanent types existing in the Divine mind." If therefore we say that the intellectual soul knows all things in the eternal types, we come back to the opinion of Plato who said that all knowledge is derived from them.

_On the contrary,_ Augustine says (Confess. xii, 25): "If we both see that what you say is true, and if we both see that what I say is true, where do we see this, I pray? Neither do I see it in you, nor do you see it in me: but we both see it in the unchangeable truth which is above our minds." Now the unchangeable truth is contained in the eternal types. Therefore the intellectual soul knows all true things in the eternal types.

_I answer that,_ As Augustine says (De Doctr. Christ. ii, 11): "If those who are called philosophers said by chance anything that was true and consistent with our faith, we must claim it from them as from unjust possessors. For some of the doctrines of the heathens are spurious imitations or superst.i.tious inventions, which we must be careful to avoid when we renounce the society of the heathens."

Consequently whenever Augustine, who was imbued with the doctrines of the Platonists, found in their teaching anything consistent with faith, he adopted it: and those thing which he found contrary to faith he amended. Now Plato held, as we have said above (A. 4), that the forms of things subsist of themselves apart from matter; and these he called ideas, by partic.i.p.ation of which he said that our intellect knows all things: so that just as corporeal matter by partic.i.p.ating the idea of a stone becomes a stone, so our intellect, by partic.i.p.ating the same idea, has knowledge of a stone. But since it seems contrary to faith that forms of things themselves, outside the things themselves and apart from matter, as the Platonists held, a.s.serting that _per se_ life or _per se_ wisdom are creative substances, as Dionysius relates (Div. Nom. xi); therefore Augustine (QQ. 83, qu. 46), for the ideas defended by Plato, subst.i.tuted the types of all creatures existing in the Divine mind, according to which types all things are made in themselves, and are known to the human soul.

When, therefore, the question is asked: Does the human soul know all things in the eternal types? we must reply that one thing is said to be known in another in two ways. First, as in an object itself known; as one may see in a mirror the images of things reflected therein. In this way the soul, in the present state of life, cannot see all things in the eternal types; but the blessed who see G.o.d, and all things in Him, thus know all things in the eternal types. Secondly, one thing is said to be known in another as in a principle of knowledge: thus we might say that we see in the sun what we see by the sun. And thus we must needs say that the human soul knows all things in the eternal types, since by partic.i.p.ation of these types we know all things. For the intellectual light itself which is in us, is nothing else than a partic.i.p.ated likeness of the uncreated light, in which are contained the eternal types. Whence it is written (Ps. 4:6, 7), "Many say: Who showeth us good things?" which question the Psalmist answers, "The light of Thy countenance, O Lord, is signed upon us," as though he were to say: By the seal of the Divine light in us, all things are made known to us.

But since besides the intellectual light which is in us, intelligible species, which are derived from things, are required in order for us to have knowledge of material things; therefore this same knowledge is not due merely to a partic.i.p.ation of the eternal types, as the Platonists held, maintaining that the mere partic.i.p.ation of ideas sufficed for knowledge. Wherefore Augustine says (De Trin. iv, 16): "Although the philosophers prove by convincing arguments that all things occur in time according to the eternal types, were they able to see in the eternal types, or to find out from them how many kinds of animals there are and the origin of each? Did they not seek for this information from the story of times and places?"

But that Augustine did not understand all things to be known in their "eternal types" or in the "unchangeable truth," as though the eternal types themselves were seen, is clear from what he says (QQ. 83, qu.

46)--viz. that "not each and every rational soul can be said to be worthy of that vision," namely, of the eternal types, "but only those that are holy and pure," such as the souls of the blessed.

From what has been said the objections are easily solved.

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SIXTH ARTICLE [I, Q. 84, Art. 6]

Whether Intellectual Knowledge Is Derived from Sensible Things?

Objection 1: It would seem that intellectual knowledge is not derived from sensible things. For Augustine says (QQ. 83, qu. 9) that "we cannot expect to learn the fulness of truth from the senses of the body." This he proves in two ways. First, because "whatever the bodily senses reach, is continually being changed; and what is never the same cannot be perceived." Secondly, because, "whatever we perceive by the body, even when not present to the senses, may be present to the imagination, as when we are asleep or angry: yet we cannot discern by the senses, whether what we perceive be the sensible object or the deceptive image thereof. Now nothing can be perceived which cannot be distinguished from its counterfeit." And so he concludes that we cannot expect to learn the truth from the senses. But intellectual knowledge apprehends the truth. Therefore intellectual knowledge cannot be conveyed by the senses.

Obj. 2: Further, Augustine says (Gen. ad lit. xii, 16): "We must not think that the body can make any impression on the spirit, as though the spirit were to supply the place of matter in regard to the body's action; for that which acts is in every way more excellent than that which it acts on." Whence he concludes that "the body does not cause its image in the spirit, but the spirit causes it in itself."

Therefore intellectual knowledge is not derived from sensible things.

Obj. 3: Further, an effect does not surpa.s.s the power of its cause.

But intellectual knowledge extends beyond sensible things: for we understand some things which cannot be perceived by the senses.

Therefore intellectual knowledge is not derived from sensible things.

_On the contrary,_ The Philosopher says (Metaph. i, 1; Poster. ii, 15) that the principle of knowledge is in the senses.

_I answer that,_ On this point the philosophers held three opinions.

For Democritus held that "all knowledge is caused by images issuing from the bodies we think of and entering into our souls," as Augustine says in his letter to Dioscorus (cxviii, 4). And Aristotle says (De Somn. et Vigil.) that Democritus held that knowledge is caused by a "discharge of images." And the reason for this opinion was that both Democritus and the other early philosophers did not distinguish between intellect and sense, as Aristotle relates (De Anima iii, 3). Consequently, since the sense is affected by the sensible, they thought that all our knowledge is affected by this mere impression brought about by sensible things. Which impression Democritus held to be caused by a discharge of images.

Plato, on the other hand, held that the intellect is distinct from the senses: and that it is an immaterial power not making use of a corporeal organ for its action. And since the incorporeal cannot be affected by the corporeal, he held that intellectual knowledge is not brought about by sensible things affecting the intellect, but by separate intelligible forms being partic.i.p.ated by the intellect, as we have said above (AA. 4 ,5). Moreover he held that sense is a power operating of itself. Consequently neither is sense, since it is a spiritual power, affected by the sensible: but the sensible organs are affected by the sensible, the result being that the soul is in a way roused to form within itself the species of the sensible.

Augustine seems to touch on this opinion (Gen. ad lit. xii, 24) where he says that the "body feels not, but the soul through the body, which it makes use of as a kind of messenger, for reproducing within itself what is announced from without." Thus according to Plato, neither does intellectual knowledge proceed from sensible knowledge, nor sensible knowledge exclusively from sensible things; but these rouse the sensible soul to the sentient act, while the senses rouse the intellect to the act of understanding.

Aristotle chose a middle course. For with Plato he agreed that intellect and sense are different. But he held that the sense has not its proper operation without the cooperation of the body; so that to feel is not an act of the soul alone, but of the "composite." And he held the same in regard to all the operations of the sensitive part.

Since, therefore, it is not unreasonable that the sensible objects which are outside the soul should produce some effect in the "composite," Aristotle agreed with Democritus in this, that the operations of the sensitive part are caused by the impression of the sensible on the sense: not by a discharge, as Democritus said, but by some kind of operation. For Democritus maintained that every operation is by way of a discharge of atoms, as we gather from _De Gener._ i, 8. But Aristotle held that the intellect has an operation which is independent of the body's cooperation. Now nothing corporeal can make an impression on the incorporeal. And therefore in order to cause the intellectual operation according to Aristotle, the impression caused by the sensible does not suffice, but something more n.o.ble is required, for "the agent is more n.o.ble than the patient," as he says (De Gener. i, 5). Not, indeed, in the sense that the intellectual operation is effected in us by the mere impression of some superior beings, as Plato held; but that the higher and more n.o.ble agent which he calls the active intellect, of which we have spoken above (Q. 79, AA. 3, 4) causes the phantasms received from the senses to be actually intelligible, by a process of abstraction.